1. Field of the Invention
The present invention relates to a portable computer system and related power supply device and charging method, and more particularly, to a portable computer system and related power supply device and charging method capable of simultaneously enhancing convenience and maintaining normal operations.
2. Description of the Prior Art
With advancement of technology and industry, portable electronic devices, e.g. notebooks, mobile phones, cameras, MP3 players, etc., have been widely used in daily life. For portability, a portable electronic device is equipped with a rechargeable battery, to provide power during operation of the portable electronic device. Since power stored in the rechargeable battery is limited, a user has to replace with another battery having sufficient power or use substitute power source to continue using the portable electronic device once power of the rechargeable battery is exhausted.
Aimed at usage of a notebook, the prior art has disclosed a dock, which includes a rechargeable battery, and connects to the notebook via a special interface, to achieve a dual-battery structure, as well as to reduce replacing frequency of batteries. For example, please refer to FIG. 1, which is a schematic diagram of a notebook 100 according to the prior art. The notebook 100 includes a rechargeable battery 102 and connects to a dock 106 through an interface 104, while other fixing mechanisms are omitted in the drawing for simplicity. The dock 106 mainly includes a rechargeable battery and may include ports of expanding interfaces, such as USB, IEEE 1394, etc. Connecting the notebook 100 to the dock 106 can add an extra rechargeable battery for the notebook 100, such that working time of the notebook 100 can be extended.
In general, after the notebook 100 is connected to the dock 106, the notebook 100 sets the rechargeable battery of the dock 106 as a discharger (or power provider), and the rechargeable battery 102 as a power sinker (or battery to be charged). In other words, when the notebook 100 is not connected to an external power source, the rechargeable battery of the dock 106 discharges to the system. After power of the rechargeable battery of the dock 106 is exhausted, the rechargeable battery 102 starts to discharge. On the contrary, when the notebook 106 is connected to an external power supply, the rechargeable battery 102 is charged first, and then the rechargeable battery of the dock 106 in turn, to ensure the rechargeable battery 102 can provide power if the dock 106 is removed instantly. However, since the notebook 100 or the dock 106 can only individually control the related charging circuit and cannot control the other charging circuit, which may result in excessive charging current, and overload a transformer. To avoid such situation, a prior art installs specific mechanism on the dock 106, which is utilized for blocking a power socket of the notebook 100 and only revealing a power socket of the dock 106 when the notebook 100 is connected to the dock 106, to keep a transformer from inserting into the power socket of the notebook 100. Another prior art utilizes a charging control device in a motherboard of the notebook 100 to control charging watts, which may result in unnecessary risk because the interface 104 has to transmit high-voltage power. Besides, the dock 106 cannot be charged when the notebook 100 and the dock 106 are separated, which deteriorates convenience.